Hacker News: front_page

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and data-source profile is covered. The description adds the ranking guarantee and enumerates the returned fields, which is useful. It does not mention rate limits, whether results are cached, or freshness of 'currently', so it adds only moderate context beyond the structured fields.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, front-loaded with the primary action, then the routing rule, then the return fields. Every clause earns its place with no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

A zero-required-parameter list tool needs little more: the description covers scope, ranking, the sibling alternative, and the return shape, while the schema handles the one optional input. Nothing an agent needs to call it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% for the single 'limit' parameter (1-30, default 10), so the schema fully documents the input. The description never mentions the limit, so it adds no meaning beyond the schema; baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('List the stories currently on the Hacker News front page') with the ranking semantics ('ranked as on the site'), and explicitly contrasts itself with hackernews_search. An agent can distinguish it from the search sibling without opening either schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives both sides of the routing decision: 'Use this to see what is trending now' versus 'use hackernews_search to find stories on a topic.' The alternative is named and the selecting condition is explicit, leaving nothing to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.